The invention relates to a device for mounting jaw casts in an articulator in the most widely used articulator systems.
To prepare dental plates or crowns and bridges, the casts made are fixed or mounted in socalled articulators for further treatment.
The conventional medium of attachment is plaster, which permits a spatial allocation of the casts. However, a great disadvantage here is the expansion of the plaster, that is to say, during crystallization (i.e., during the curing), it is impossible to control the change in volume of the plaster, thus resulting in an undesirable tolerance of the work result. Among other drawbacks is the long setting time of the plaster.
The mounting with plaster of casts in an articulator results, during the setting phase, in an expansion of the plaster because of the crystallization process. The degree of this plaster expansion is dependent upon the height of the plaster base. Laboratories operating with a high degree of precision minimize this effect by mounting the casts in several layers of plaster, which, naturally multiplies the already time-consuming setting time of the plaster, and this is another drawback.
Also, the resultant soiling of the articulators, particularly because it is often necessary to knock out the casts after the work has been completed, leads to damage of the precision instruments.
An incorrect occlusal position can be rectified only by removing one of the plaster bases and mounting the corresponding jaw cast by means of plaster in an articulator after another registration. This time-consuming procedure calls in most cases for another session for the patient, and there is still no guarantee at all that, after another corrective session, the patient has obtained the correct occlusal position during the last registration.
Other disadvantages are: the plaster support plates of the articulators can be reused only a few times, the mixing of the plaster alone results in a loss of time and makes subsequent clean-up operations necessary.